unittest

What unittest is

unittest is Python’s unit testing framework for automating tests and organizing their setup and execution. It provides fixtures, TestCase classes, TestSuite collections, and test runners, so you can structure tests and run them independently of the reporting framework. TestCase includes assertions such as assertEqual, assertTrue, assertFalse, and assertRaises. You can start tests from the command line by module, class, method, or file path; running without arguments starts discovery. Discovery can be configured with a start directory, filename pattern, and project top-level directory. Tests and classes can be skipped, tests can be marked as expected failures, and subTest can identify individual iterations and report parameters when one fails. The documentation also points to unittest.mock for using mock objects. unittest supports Python on Linux, macOS, and Windows, and is free to use and distribute, including commercially. One discovery constraint: test files must be importable modules or packages from the project top-level directory.